Electric valve device



Aug. 9, 1949.

H. KELLER ET AL 2,478,764

ELECTRIC VALVE DEVICE Filed Oct. 22, 1945 Patented Aug. 9, 1949fatter-Ric vALvi: tenet A Blaitrfwitfij iiid Wernerrmsbersteg, Baden,(sw ngin ellschiflt Brown, 'Botii'i signers as we P l 010', Baden;'SWitirland, a. joint-stock 6615i pany of Switzerland kfiiiiicttidtniiit.

In San I122, art-semi f Nove ber 13; 1944 3 ohms. (c1. 3:15;:261-9invention sen re electric t me devises. such ilgriitrbn devices halting9} mercury pobl cathode, eat it has particular re lation to theeaesgitan cf the ignitiori eieetrene or igniter. Such d r s havemutatcrs." However; for present purposes they will be referred to asigiiitr'on's. v

Care must be taken sens the igfiitihg er single anode tofestabii-sh thesti=alld cathode spot; e'it er continuously by constant energizatioiiiiiimpulse control for that surpass, continuous energization,precautions arenecessary to avoid are back as a result of the continuousionization and vapor development during half-cycleswhen the anode isnegative. Auxiliary series-current circuits are required withthe pr io rimpulse control systems to insure ignition during the desired periodsthat may be of fixed duration or of adjustable dura-' pn a ,v ri d. by.hasent e nt e impmse All of ese rstemsse re asqmnlicate the a paratusand increase the energy required for the auxiliary de i es,

.ccq d n 3.! t n a ject. i this invention, to providejmprovedarrangements for establishing e ath d s qt Qt e en tmn u. V

Anoti erpbje611,isl O redu he likelihood of are back at the anode ofignitron type devices.

A further object is to cause direct current to flow at all times throughthe igniter of an ignitron at a value just sufficient to maintain thecathode spot after it is once established.

Other objects of the invention will, in part, be obvious and will inpart appear hereinafter.

For a more complete understanding of the nature and scope of thisinvention reference can be had to the following detailed descriptiontaken with the drawing in which:

Figures 1 and 2 illustrate, diagrammatically, two preferred embodimentsof the invention.

According to this invention, a direct current is passed continuouslythrough the igniter, the current being of limited magnitude and justsumcient to maintain the ignited cathode spot in the immediateneighborhood of the igniter under normal or favorable operatingconditions. A substantially continuous maintenance of the cathode spotis insured by the provision of mechanism or circuit arrangements forautomatically increasing the voltage on the igniter electrode if thecathode spot is extinguished.

Referring now particularly to Figure 1 of the drawing it will be notedthat the reference character I0 denotes an ignitron having an anode II,a mercury cathode l2 and an igniter I 3, the lat- 55 tq'a scarce at resttar et it, ted direct "r k I maintain substantially to 'ciirrn't the igniter l3 and the latter serving ttfiifiiit the not; means. 1 reefgi'i'itlhii'iiniilfiite igniter a ticrender the arepiovided bygenerally by numeral 2 2.

aerate, inst I This-device intiu transformer pay ng a trail 2i can?neeted'for eaergizatioa at the aittrfiatiiig source, and a secondarywinding 1 which at 8 nested through a rectifier 25 to denserifii Thecondenser 23 aiseharg re a glow. tube 21 and the igniter 13- wiresecntacts, 28 are closed by an armature 2 9 on ergization of a winding 30which is connected between the conductors l4 and [5, as shown.

In operation, assuming that the circuit to the motor I! is energizedwith alternating current, the motor I! drives the generator I6 andoperating voltage is applied across the conductors l4 and 15. Thewinding 30 is energized and attracts armature 29 to close the contacts28. In the meantime, condenser 26 has been charged through the rectifier25 by the transformer 23, 24. The condenser 26 discharges through theglow tube 21 and over the contacts 28 to form the cathode spot on theigniter l3 and render the ignitron ID conducting. As soon as it becomes,conducting, the voltage between the conductors I4 and I5 drops to suchvalue that it is insumcient to maintain the winding 30 energized to theextent necessary to hold contacts 28 closed. Accordingly, the contactsopen and only the limited voltage from generator I6 is imposed on theigniter electrode 13.

If for any reason the cathode spot should become extinguished, thevoltage across the conductors l4 and I5 rises and winding 30 isthereupon energized sufilciently to close contacts 28. The cycle aspreviously described as discharge of the condenser 26 is repeated tore-establish the cathode spot. After the cathode spot has been 3 formed,it is maintained by the current supplied by the generator [6. Thiscurrent is relatively small as compared to the impulse current that issupplied by the discharge of the condenser 26 to produce the cathodespot.

The supplying of the igniter [3 with direct current, as described, hasthe advantage that the cathode I2 is enabled to yield a substantiallyhigher cathode current. The amount of vapor that is produced is afraction of that produced by the prior continuous excitation methods sothat the performance of the ignitron I is not impaired. In thisoperation the igniter [3 can be used to fix the cathode spot.

If at first, during the initial breakdown of the ignitron II], nocathode spot is produced, additional shocks or impulses will be appliedthrough the glow tube 2! but only if the condenser 26 is charged so highthat the breakdown voltage of the glow tube 21 is exceeded.

.Instead of the generator l6, any other suitable source of directcurrent may be employed.

As shown in Figure 2, vibrating means 34 can be provided for producingthe cathode spot. For example, the vibrating means 34 may be of theelectromagnetic type energized from the alternating current sourcethrough a switch 35 to reestablish the cathode spot it it isinadvertently extinguished. Thereafter a current of 2 to 3 amperes fromthe generator I6 is sufficient to maintain the cathode spot. It will benoted that. when the vibrating means 34 is provided, the impulseproducing means orshock device 22, shown in Figure 1, is unnecessary.

We claim:

' 1. The combination with a cathode pool type vapor electric valvehaving a resistance igniter for initiating conduction between the anodeand cathode of the valve by the formation of a cathode spot, of a sourceof direct current, circuit means connecting said source of directcurrent to said igniter, means limiting the direct current flowingthrough the igniter to a value just sufficient to maintain the ignitedcathode spot in the immediate neighborhood of the igniter, a condenserand a current source for charging the same constituting a currentpulsing device for both initially establishing the formation of thecathode spot and reestablishing the same upon an extinction thereofduring operation of the valve, and switch means controlled in accordancewith the impedance of said circuit means for temporarily connecting saidcondenser to said igniter to discharge through the same.

2. The combination with a cathode pool type vapor electric valve havinga resistance igniter for initiating conduction between the anode andcathode elements, of a source of direct current, circuit meansconnecting said source between the igniter and cathode pool, meanslimiting the fiow of direct current through the igniter to a value justsuficient to maintain the cathode spot in the vicinity of the igniteronce it has been established, a condenser and a current source forcharging the same constituting a pulsing device for initiallyestablishing the cathode spot and for reestablishing the same upon anyextinction thereof during the time that the valve is operating, switchmeans for connecting said condenser to said igniter to discharge throughthe same, and relay means energized upon extinction of the cathode spotfor closing said switch means.

3. A system for igniting cathode pool type valves as defined in claim2wherein the energizing winding of said relay means is connected betweensaid igniter and. cathode pool.

HANS KELLER. HANS BLATTER. WERNER IMOBERSTEG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

